Effect of Chamomile Hydroalcoholic Extract on Bleomycin-Induced Pulmonary Fibrosis in Rat

Background: The aim of the present study was to investigate the effect of the Chamomile hydroalcoholic extract on bleomycin-induced pulmonary fibrosis in rat. Materials and Methods: Rats (N.Mari, 180–220 g) of either sex were given a single intratracheal instillation of bleomycin (7.5 IU/Kg) or the vehicle (saline). Treatment groups were given the same dose of bleomycin and then received different doses of oral chamomile hydroalcoholic extract (400, 600, 800, 1000, and 1500 mg/kg/day) for two weeks. Results: Histological and pharmacological experiments of bleomycin-treated animals showed that bleomycin could cause marked pulmonary fibrosis within two weeks. In addition, administration of Chamomile hydroalcoholic extract reduced such damages in lung tissue in a dose-dependent manner. Best results were obtained with 1500 /kg/day of Chamomile hydroalcoholic extract. Conclusion: From the results of current study, it can be concluded that Chamomile hydroalcoholic extract may be able to diminish the toxic effects of bleomycin on the lung tissues. Such effect of Chamomile can be attributed to the ingredients of this plant with anti-inflammatory and anti-oxidant properties.


INTRODUCTION
Bleomycin is an antibiotic reagent with anti-tumor, anti-viral and antibacterial properties. Bleomycin is generally used in multi-drug chemotherapy due to its minimum bone marrow and immune system depression and is considered as a typical cytotoxic anti-neoplastic agent (1). Nonetheless, administration of Bleomycin may result in severe and chronic pulmonary fibrosis. DNA conjugation and production of superoxide apart from other oxygen activated reagents and hydroxyl radicals, are reported as bleomycin mechanisms of action (2,3). It is assumed that this abnormality is a marker of inflammatory response in the alveolus. In one type of alveolus damage interstitial edema and accumulation of inflammatory cells occur (alveolitis) (4).  (7), anti-neoplastic effect on breast and uterine cancer cells in vitro (10-100 µg/ml concentration) (8), benzodiazepine-like activity (9) and phosphodiestrase inhibitory action (leads to increased cAMP levels) (10).
Although few treatment methods have been suggested to prevent the primary and advanced state of pulmonary fibrosis (5) (11)(12)(13).
The aim of the present study was to evaluate the antiinflammatory and anti-oxidant effects of M. chamomilla plant in bleomycin-induced pulmonary fibrosis.

Experimental groups and treatment regimens
Experimental animals were divided into three major groups.

Histological evaluation
After a two weeks period the experimental animals were anesthetized with 0.3 ml thiopental (120 mg/kg) and scarified and then lungs were removed; the left lobe of lung tissue was fixed in 10% formalin solution for histological studies. In the next step a mid-sagittal section of each lung was prepared at 5 μm thickness and stained with Hematoxylin and Eosin (H&E). In order to evaluate the pathological grade caused by inflammation and fibrosis in the whole area and connective tissue changes apart from interstitial fluid particularly collagen, the prepared samples were stained with reticulin. In the following, the sections were evaluated by light microscopy.

Pharmacological experiments
In the recent study, isolated lung tissues were used for

Statistical analysis
After addition of contraction constituents to bath and obtaining pulmonary contraction responses, the tension (mg/mg weight) against concentration was plotted. In this study, the results were expressed as mean ± SD. Paired Student's t-test and analysis of variance were performed in order to determine the significant differences between means. P< 0.05 was considered statistically significant.

Histological results
After

Pharmacological results
In the recent study, lung tissue in group receiving 1500 mg/kg Chamomile hydroalcoholic extract was studied in  The anti-inflammatory potential of Chamomilla recutita was shown clinically in patients with phlebitis due to antineoplastic chemotherapy (6). Chamomile caused significant inhibition on proinflammatory cytokines production IL1β, IL-6 and TNF-α (14). It was shown that Chamomile is a selective COX-2 inhibitor with antiinflammatory activities (15). All these data showed that Chamomile has well-known anti-inflammatory and antioxidant activities. It was also demonstrated that antiinflammatory effects may be mediated through inhibition of Nitric Oxide (NO) production (14).
Different studies were performed in regard to prevention and treatment of pulmonary fibrosis by administration of vitamin E (5) or non-steroidal antiinflammatory drugs such as indomethacin and diclofenac (13). Since Chamomile plant contains great amounts of anti-inflammatory agents it can also be used to prevent and treat pulmonary fibrosis (11).
In the recent studies, the effect of the Chamomile hydroalcoholic extract on pulmonary fibrosis was evaluated. They demonstrated that herbal flavonoids can inhibit the production of prostaglandins and leukotrienes in rat (14,15). Histological evaluation illustrates that the A part from medicinal properties, several reports has raised concern about the toxic effects of Chamomile such as allergic reactions following oral administration (20) and contact dermatitis following topical applications (21,22).
Furthermore, Chamomile preparations contain components, especially chamazulene, Cis-spiroether and trans spiroether which showed in vitro inhibitory activities of major human drug metabolizing enzymes (23). Thus, the potential of interaction between Chamomile and drugs should be considered.
In the present study the anti-inflammatory potential of Chamomilla recutita was shown. As a conclusion, administration of Chamomile extract due to its advantages is suggested in patients receiving long-term bleomycin sulfate or subjects exposed to fibrogenic materials or fibrotic damages.